Multi-circuit switching connector

ABSTRACT

A multi-circuit switching connector of the plug and jack type for patching multi-circuit electrical systems to perform patched switching and coupling of source and load equipment. The switching connector includes a female jack having a pair of plug receiving barrels disposed in side-by-side spaced parallel relation and first and second sets of insulated contact elements disposed in fixed laterally opposed relation along the respective plug receiving barrels in rows parallel to the axes of the respective barrels for limited movement transversely of the barrel axes from a normal position establishing a through circuit between the opposed contacts; a pair of patching plugs each having a third set of mutually insulated contact elements disposed in longitudinally spaced relation axially of said plugs and arranged to respectively be engaged with the first and second set of contact elements; and coacting means on the respective plugs and the pair of plug receiving barrels orienting the plugs in predetermined angular relation for full entry into the barrels and rotation when fully inserted to patched engagement of the respective third sets of contact elements with the first and second sets of contact elements to selectively shift either or both of said first and second sets of contact elements from their normal positions to a shifted position to disrupt the through circuit and patch the circuits of the shifted contact elements through the associated patching plug.

United States Patent Lancaster [54] MULTl-CIRCUIT SWITCHING CONNECTOR [72] Inventor: Jesse F. Lancaster, Great Falls, Va. [73] Assignee: Cooke Engineering Company, Alexandria,

[22] Filed: June 23, 1964 [21] Appl.No.: 377,270

[52] U.S. Cl ..200/51.07, ZOO/51.12, 179/96,

339/182, 339/183 [51] Int. Cl ..HOlr 19/50 [58] Field ol'Search ..200/51.095l.1 1,

200/5l.065l.07,51.l7,166.1,155, l53.l3,51.l2; 317/99; 339/113, 182 R, 183,189.17 F; 179/96,

[56] References Cited UNITED STATES PATENT S 3,077,523 2/1963 Clewes ZOO/51.09 3,202,953 8/1965 Bosworth et a1. ..339/182 592,315 10/ l 897 Kellogg 179/62 2,169,988 8/1939 Norrito..... 179/96 2,434,534 1/1948 Alford ..339/113 2,507,744 5/1950 Welch ..200/166 1 3,001,167 9/1961 Chestnut et al.. ZOO/51.13 3,034,091 5/1962 Gluck l ..339/17 3,158,422 11/1964 Bowden et al. ..339/183 [451 May 23, 1972 Primary ExaminerDavid Smith, Jr. Attorney-Strauch, Nolan, Neale, Nies & Kurz ABSTRACT A multi-circuit switching connector of the plug and jack type for patching multi-circuit electrical systems to perform patched switching and coupling of source and load equipment. The switching connector includes a female jack having a pair of plug receiving barrels disposed in side-by-side spaced parallel relation and first and second sets of insulated contact elements disposed in fixed laterally opposed relation along the respective plug receiving barrels in rows parallel to the axes of the respective barrels for limited movement transversely of the barrel axes from a normal position establishing a through circuit between the opposed contacts; a pair of patching plugs each having a third set of mutually insulated contact elements disposed in longitudinally spaced relation axially of said plugs and arranged to respectively be engaged with the first and second set of contact elements; and coacting means on the respective plugs and the pair of plug receiving barrels orienting the plugs in predetermined angular relation for full entry into the barrels and rotation when fully inserted to patched engagement of the respective third sets of contact elements with the first and second sets of contact elements to selectively shift either or both of said first and second sets of contact elements from their normal positions to a shifted position to disrupt the through circuit and patch the circuits of the shifted contact elements through the associated patching plug.

13 Claims, 19 Drawing Figures Patented May 23, 1972 7 Sheets-Sheet 1 INVENT( )R JESSE FRANK LANCASTER ATTORNEY Patented May 23, 1972 7 Sheotrs-5heet 2 INVENTOR JESSE FRANK LANCASTER BY v M 77% $72M ATTORNEY Patented May 23, 1972 3,665,129

'7 Sheets-Sheet 4 JESSE FRANK LANCASTER ATTORNEY Patented May 23, 1972 7 Sheets-Sheet 5 R O T N E V m JESSE FRANK LANCASTER ATTORNEY Patented May 23, 1972 7 Sheets-Sheet 7 til I 32 347 OUT 6 9 3 f T T T U U U U O O O O JESSE FRANK LANCASTER BY M, 7134/ a! M ATTORNEY MULTI'CIRCUIT SWITCHING CONNECTOR This invention relates to electrical connectors, particularly plug-in type connectors which couple and switch plural sets of parallel conductors.

In setting up, testing, and maintaining electrical systems, it is frequently necessary or desirable to selectively connect various multi-lead electrical components to the system. Depending upon the particular application, this selective connecting or circuit patching may introduce a component in series with the system or in any other commonly known circuitry pattern such as double series, double parallel, normal through, looping, holding loop, or set jack arrangements.

Prior art connectors designed to perform combined switching and coupling functions have been bulky devices not adapted for miniaturization. As shown by US Pat. No. 1,958,901 to Schramm and No. 2,312,002 to Schmitt, these devices have commonly utilized a plug having a plurality of parallel pins inserted in corresponding holes in a mating part. This type of device necessitates careful alignment of the mating parts before insertion and requires considerable panel space as the minimum pin size is limited by pin stiffness and strength requirements and as appreciable spacing is necessary between the pins to prevent arcing. Further, when plugs of this type are not connected, the pins of the male plug are exposed and are therefore easily damaged or short circuited.

As shown by US. Pat. No. 1,834,184 to Schramm and No. 2,434,534 to Alford, another type of prior art connector incorporates a plurality of pins extending radially outwardly from a plug which is axially insertable in a mating jack, but these devices are basically merely connectors without any inherent switching action, Circuit switching in these connectors is only obtained by ancillary switches adjacent to the connector which are adapted to be operated by auxiliary mechanical means when the plug is inserted and rotated. These ancillary switches add bulk and complicate the structure of such connectors.

Accordingly, a primary object of this invention is to provide multi-conductor switching connectors which are more compact, more durable, simpler, safer, and easier to use than those of the prior art.

To accomplish this object, the invention provides a multicircuit switching connector having a single-pin, male plug connected to a cord having a set of parallel conductors which terminate in a plurality of longitudinally aligned electrical contacts spaced along the axis of the plug. A mating female jack having a set of parallel switch circuits including contacts spaced along the insertion axis of the plug is also provided. The plug is adapted to be fully axially inserted in the jack before any coupling or switching of circuits occurs. Then upon a partial turn of the plug, the contacts on the plug connect with and actuate the contacts in the jack circuits to accomplish the desired circuit switching.

Further objects of the present invention include:

1. The provision of multi-conductor connector switches designed for miniaturization and the incorporation of printed circuits therein;

. The provision of multi-circuit, plug-in type switching connectors wherein the electrical switching and connecting functions for each circuit are accomplished by one element ofthe plug; and

. The provision of a multi-circuit jack in combination with two multi-conductor plugs each operative upon engagement in said jack to effect a switching and connecting function with the jack circuits and the plug conductors.

These and other objects of the present invention will appear from the following description and the appended claims when read in conjunction with the accompanying drawing wherein:

FIG. 1 is a graphic representation of the proper arrangement for the sheets of drawing bearing FIGS. 1A, 1B, and 1C to form an interrelated exploded view of a connector according to the present invention;

FIG. 1A is an exploded perspective view of one plug for the connector of FIGS. 1A to 1C;

FIG. 1B is an exploded perspective view of a jack which receives the plug of FIG. 1A;

FIG. 1C is an exploded perspective view of a cable adapter which connects with the jack of FIG. 1B;

FIG. 2 is a fragmentary perspective view of a protective dust cover for the jack of FIG. 1B;

FIG. 3 is an exploded perspective view showing some of the components of a barrel assembly for the jack of FIG. 1B;

FIg. 4 is a transverse vertical section through the jack of FIG. 1B, as assembled, and shows two of the plugs of FIG. 1A inserted therein;

FIG. 5 is a partially exploded, perspective view of a modified embodiment of a connector according to the present invention;

FIG. 6 is a transverse vertical section through the jack and a plug of the connector of Flg. 5;

Hg. 7 is an enlarged, fragmentary, transverse, vertical section similar to FIG. 6 but shows a plug oriented for axial insertion in the jack;

FIG. 8 is a top view of a jack of another modified embodiment of a connector according to the present invention;

F Ig. 9 is a side view of the jack of FIG. 8;

FIG. 10 is a partially sectioned top view of a plug for the jack of FIG. 8;

FIG. is a schematic illustration of the switching circuitry of the connectors shown in the foregoing figures; and

FIGS. 12 to 16 are schematic illustrations of other switching circuits feasible with connectors according to the present invention.

As shown in FIGS. 1 to 4, a connector 20 (FIG. 4) includes plugs 22 (one plug being shown in exploded perspective view in FIG. 1A) adapted to be inserted into barrels 26 and 28 of a jack 30 (FIG. 1B). The various switching circuits of jack 30 are connected by a printed circuit board 32 to a plurality of parallel male pins 34 and 35 at the rear of the jack. When assembled, the jack 30 is enclosed by dust cover 36 (FIG. 2) leaving access to jack barrels 26 and 28 at the front end of the jack and to connecting pins 34 and 35 at the rear thereof. A cable adapter unit 38 is provided to closely fit against the rear end of dust cover 36 to connect male pins 34 and 35 with individual conductors of multi-conductor jack cables (not shown) entering adapter unit 38 through cable terminating tubes 40 and 42.

PLUGS 22 As shown in FIGS. 1A and 4, a plug 22 of connector 20 includes a main tubular plug body 44, a front guide 43, a cord terminating tube 45, and a finger-grip cap 46. Main plug body 44 has milled into its exterior surface a longitudinal alignment groove 47 terminating in an offset enlargement 48 at the rear thereof to permit a bayonet type engagement with jack 30 as more fully described below. The rear end 51 of plug body 44 is rigidly secured to cord terminating tube 45 by a pressed and soldered fit. The opposite end 52 of cord terminating tube 45 is internally threaded to receive a threaded end 54 of knurled finger-grip cap 46.

A plug cord (not shown) is assembled in plug 22 by inserting it through a central bore 58 in cap 46, through a brass washer 60 and a rubber washer 62, through a narrowed bore portion 64 in cord terminating tube 45 and into the interior of tubular plug body 44. The cord is secured in position in the plug by threading cap 46 into cord terminating tube 45 with washers 62 and 60 within the tube and adjacent to narrowed portion 64. Tightening cap 46 compresses rubber washer 62 so that it expands radially inwardly to retainingly grip the plug cord.

At the head end of plug body 44 an axial slot is cut through its tubular side wall at a position generally opposite from alignment groove 47. Slot 70 extends approximately half the length of tubular body 44 and snugly receives an insulating contact insert 72.

Contact insert 72 is radially through drilled in a plurality of longitudinally aligned, axially spaced positions to receive hollow pins 76 of semi-cylindrical plug contacts 78. As best shown in FIG. 4, the contact pins 76 are retainingly flared at their inner ends and have holes 80 therein to receive a single insulated conductor such as 82 and 84 (FIG. 4) of the plug cords.

As shown in FIG. 1A, insert 72 is retained in slot 70 by front guide 43 which fits over an annular cut away portion 86 provided at the front end of tubular plug body 44. The front guide has an longitudinal alignment groove 88 forming a continuation of groove 47 in plug body 44 and has a radially projecting guide pin (not shown) on the other side thereof in longitudinal alignment with contacts 78 to assist in aligning the plug for insertion in jack 30. Guide 43 is retained on plug body 44 by screws 90 extending through countersunk holes 92 in an annular wall 94 at the rear of guide 43, through the holes 95 in the cut away portion 86 of plug body 44, and into threaded holes (not shown) in a central cylindrical portion 96 of the front guide.

JACK 30 As shown in FIGS. 18 and 4, jack 30 includes a main jack body 100 having two longitudinal bores 102 (FIG. 4) to receive jack barrels 26 and 28 of a jack barrel assembly 104 (partly shown in the exploded view of FIG. 3). Jack barrel assembly 104 includes jack barrels 26 and 28 together with a plunger 106 and a compression spring 108 contained within the rear end of each barrel.

Jack barrels 26 and 28 each have a longitudinal key slot 1 10 cut through the barrel wall at the bottom of the front end thereof. An alignment key 112 is rigidly soldered in position within each slot so that an extension 114 on the bottom of the key protrudes radially downwardly from the outer cylindrical surface of the jack barrel and so that the upper surface 116 of the key extends above the inner cylindrical surface of the jack barrel throughout the length of the key. Barrels 26 and 28 with alignment keys 112 fixed therein are inserted in bores 118 and 120 of front plate 122 so that the lower extensions 114 on the alignment keys fit coextensively within longitudinal notches 124 and 126 provided at the bottom of bores 118 and 120, respectively. Barrels 26 and 28 are rigidly secured in this position in front plate 122 by soldering.

Barrel assembly 104 is inserted as a unit within jack body 100 with compression springs 108 abutting the rear end of jack body bores 102 to bias plungers 106 forwardly. Barrel assembly 104 is retained in jack body 100 by means of a screw 130 threaded into a suitable threaded hole (not shown) in the jack body.

The side walls of jack barrels 26 and 28 are cut through in longitudinally extending slots 132 which have offset lateral enlargements 134 at the rear thereof for purposes described below.

As shown in FIGS. 18 and 4, jack body 100 has a transverse cut away portion 135 across its upper surface to provide open access to the slot enlargements 134 in barrels 26 and 28. Cut away portion 135 terminates in flat surfaces 136 outboard of barrel bores 102 and in a grooved surface 138 therebetween. Center conducting strips 140 are mounted in grooves 144 of central surface 138 and are retained therein by pins 142 soldered thereto and extending downwardly in tight relation within vertical bores 146 in the jack body.

Insulating block 150 (FIGS. 1B and 4) are mounted upon the outboard surfaces 136 of body 100 and snugly contain conducting pins 152 in bores 153 therein. Spring strips 156 and 157 which may be phosphor bronze springs are mounted upon the upper ends of pins 152 and lie in grooves 158 provided in upper surface of the insulating blocks 150. The upper ends of the pins 152 are flared over spring strips 156 and 157 and soldered thereto at 160 thereby retaining the pins and the blocks in assembled relation with annular flanges 161 of pine 152 tight against the bottom of the insulating blocks within a countersunk portion 163 therein. Insulating covers 162 having circular cut away portions 164 in the lower surface thereof are provided to cover the upper ends of pins 152 and are retained in place upon insulating blocks 150 by screws 166 extending through the covers 162, the insulating blocks 150, and into threaded bores 168 provided in jack body 100.

Spring strips 156 and 157 have center contacts 170 at the free end thereof which normally engage center conducting strips 140 and also have plug contacts 172 which normally extend into the enlargements 134 in the side walls of barrels 26 and 28. Contacts 170 and 172 extend through suitable holes in the spring strips 156 and 157 and are peened over for retention therein.

Circuit board 32 is mounted upon the bottom of jack body 100 over end extensions 176 of pins 152 which protrude from vertical pin receiving bores 177 in jack body 100. Extensions 176 fit through suitable holes 178 provided in the ends or terminals of the printed circuits of the circuit board, and are cut off flush with the circuit board and soldered thereto as at 180. As shown in FIG. 115, a terminal 182, for example, is connected by a printed circuit 184 to an after terminal 186 at the rear of the circuit board, and terminal 188 is connected by a printed circuit on the lower surface of the circuit board (not shown) to a forward terminal 190 at the rear of the board. The remaining terminals are connected to similar manner by circuits printed on the upper and lower surfaces of the board.

Jack body 100 has a rearwardly extending ledge 194 to receive a parallel pin connector assembly 196 thereupon. Assembly 196 includes a lower block 198 having a set of vertically extending holes 200 drilled in alignment with a set of vertical through holes 202 in ledge 194. A set of male conducting pins 35 extends downwardly through holes 200 and 202 to protrude below jack body 100 through holes 204 provided in the after terminals such as 186 in the printed circuit board. Pins 35 are bent 90 at the upper surface of lower block 198 and have horizontal portions 206 extending along longitudinal grooves in the upper surface of block 198 and in the lower surface (not shown) in an intermediate block 208 to protrude from the rear of the jack.

Parallel pins 34 of another pin set similarly have horizontal portions 212 extending in longitudinal grooves formed in the upper surface of intermediate block 208 and in the lower surface (not shown) of an upper block 214. Pins 34 also have a 90-bend and extend downwardly through vertical holes 216 in the intermediate and lower blocks and through holes 217 in ledge 194 to protrude below the jack body through holes 218 drilled in the forward terminals such as 190 in the printed circuit board. Upon assembly of the board to the jack body, pins 34 and 35 are trimmed off and connected thereto in a manner similar to that described for pins 152. Connector assembly 196 is retained on ledge 194 of jack body 100 by means of screws 219 extending through the upper, intermediate, and lower blocks and into threaded holes 220 in ledge 194.

The assembled components of jack 30 are enclosingly protected by dust cover 36 which not only excludes foreign matter but also functions as an electrical shield for the circuits therein. It extends from the front surface of front plate 122 to a position just rearward of protruding pins 34 and 35 and is retained on the jack by screws (not shown) extending through countersunk holes 221 at the front end thereof into threaded bores 222 in front plate 122. The dust cover further has elongated apertures 280 at the rear thereof for purposes described below. ADAPTER UNIT 38 As shown in FIG. 1C, adapter unit 38 is provided to removably connect the male pins 34 and 35 protruding from the rear of jack 30 with multi-conductor jack cables (not shown). Accordingly, adapter unit 38 includes an insulating block 230 containing a plurality of tubular female pins 232 extending through longitudinal bores 234 provided in the block. The male pin receiving end of tubular pins 232 is provided with a diametric, longitudinally extending slot 236 to provide a resilient but snug connection between the male and female pins. The opposite ends 238 of pine 232 are partially cut away to facilitate the insertion of a like terminal fixtures conventionally used to connect the conductors of a multi-wire cable to terminal block.

Insulating block 230 also contains two alignment pins 240 which are provided to fit in alignment bores (not shown) drilled in the rear edge of ledge 194 of jack body 100 to facilitate the coupling of jack 30 with adapter unit 38. Further,

tab spring plates 242 are mounted on protruding portions 244 of insulating block 230 for purposes described below.

Insulating block 230 with spring plates 242 fits within adapter unit shell 246 with spring tabs 248 of spring plates 242 fitting within notches 250 provided in the adapter shell. Shell 246 in turn fits within an electrically shielding adapter cover 252, and the above parts of cable adapter unit 38 are secured together by machine screws 254 extending through countersunk bores 256 in cover 252, bores 258 in shell 246, bores 260 in spring plates 252, and into threaded bores 262 in insulating block 230.

The multi-conductor cables (not shown), which provide the individual electrical connections to female pins 232, extend respectively through terminating tube caps 264 and 266, brass washers 268, rubber washers 270, cable terminating tubes 40 and 42, and into the interior space within adapter cover 252 and behind insulating block 230. In a manner similar to that described for the cord retaining elements of the plugs 22, the multi-conductor cables are firmly gripped in cable terminating tubes 40 and 42 when caps 264 and 266 are respectively threaded into the tubes 40 and 42 thus compressing rubber washers 270 between brass washers 268 and narrowed bore portions 272 located at the adapter cover end of the cable terminating tubes.

Upon assembly of jack 30 to adapter unit 38, dust cover 36 abuts adapter cover 252 to form an encompassing, protecting, and electrically shielding enclosure for the switching connector of the present invention. The elongated apertures 280 in dust cover 36 are resiliently engaged by spring tabs 248 of the adapter unit to retain the components in assembled relation.

SET UP AND OPERATION In a typical installation, the connector of the present invention is mounted in an electrical panel, and in one specific embodiment, the connector is of such small size that 26 connectors can be stacked in a standard 19 by l-% inch panel. Multi-conductor cables located at the back of the panel are permanently connected to the female pins of cable adapter unit 38 of each connector. Jacks are electrically connected to the adapter units 38 by the coupling of male pins 34 and with female pins 232 and are resiliently retained therein by means of the engagement of the jack dust cover apertures 280 with spring tabs 248 of the adapter units. Thus, the connection between each jack and its adapter unit is one which can be easily unplugged, and a jack having an alternate switching circuitry, as described below, may be substituted for jack 30.

The assembled unit composed of the jack and the adapter unit is located flush with the electrical panel with jack barrels 26 and 28 protruding therethrough to the front side of the panel. Plugs 22 are permanently attached to multi-conductor cords (not shown) as hereinbefore described which are located in front of the electrical panel.

Convenient and quick connection of the conductors of the plug cords with the conductors of the jack cables can be accomplished by axially inserting plugs 22 in jack barrels 26 or 28 with alignment keys 1 12 interfitting in alignment slots 47 of the plugs. Plugs 22 can be completely axially inserted in the jacks without any connecting or switching of the circuits as is shown by the cross section of the right-hand plug in FIG. 4. However, when the plug has been completely inserted, the plug bayonet enlargement 48 is adjacent alignment key 112 and permits clockwise rotation of approximately 20, in one specific embodiment, of plug 22 in the jack barrels 26 or 28 to complete the contact and switching functions of this connector, as shown in the cross section of the left-hand plug in FIG. 4.

CIRCUITRY MODIFICATIONS Flg. 11 shows a schematic illustration of the switching circuitry of jack 30 described above. In this diagram a conductor 184 represents one of the plurality of input conductors which may be connected to the contact spring strips 157 on the righthand side of jack 30. Center strip normally makes a through electrical connection to spring strip 156 on the lefthand side of jack 30 which connects with output conductors on that same side of the jack. However, when plugs 22 are inserted in the jack 30 the normal through connection via center strip 140 is broken as plug contacts 78 engage jack contacts 172 and raise the spring strips 156 and 157. The circuitry is thus changed to serially include a patch circuit 320 connected between the two plugs 22.

In FIG. 12, a modified jack 330 includes a plurality of normal input, spring strip conductors 332 normally connected by contacts 333 to spring strip conductors 334 of a circuit 336 which is completed by spring strip conductors 338 through contacts 339 to output spring strips 340. Upon insertion of a modified plug 342 having a pair of axial rows of contacts 344, the input conductors 334 are lifted and disconnected from the conductors 332 at contacts 333, and conductors 332 are reconnected to cross-over conductor 346 by contacts 347. Similarly output conductors 341) are disconnected from conductors 338 at contacts 339 and are reconnected at contacts 348 to the cross-over conductor 346. In this manner upon insertion of plug 342 the normal input and output leads 332 and 340 respectively are directly connected, and circuit 336 is reconnected to the two sets of leads 350 and 352 of plug 342.

As shown in FIG. 13, a modified jack 354 has normal input lead spring strips 356 connected by contacts 358 to center spring strips 360 which in turn are connected by contacts 362 to output conductor strips 364. Upon insertion of one or two double plugs 366 the normal through connection is broken at contacts 358 and a patch circuit 368 is inserted in series with the input conductor 356 and the output conductors 364. A second plug (not shown) similar to plug 366 may be inserted to break normal through connection contacts 362 to insert another patch circuit in series with the input and output leads.

As shown in FIG. 14, a modified jack 370 has a plurality of spring strip, input leads 371 connected at contacts 372 to a cross-over connections 373 connected at contacts 374 to normal output conductors 375. Upon insertion of a plug 376 the connection at contacts 372 is broken and a patch circuit 377 connected to plug 376 is connected to input conductors 371 and to center conductors 378. Until a second plug 379 having a patch circuit 380 connected thereto is inserted in the lefthand side of jack 370 there are no complete connections, but upon insertion of such jack 379, the center conductor 378 is further serially connected through the patch circuit 380 of plug 379 and to output conductors 375.

As shown in FIG. 15, a modified jack 380:: has a plurality of double contact input spring strips 381 which normally contact corresponding lower center strips 382, which in turn normally connect with output spring strips 383. Upon insertion of a plug 384 in the right-hand of side jack 380a, a momentary break in the normal through circuit occurs as spring strips 381 shift to contact upper center bar contacts 385 and at the same time connections are established between input leads 381 and plug circuits 386. A second plug (not shovm) may be similarly connected to the through circuits in the left-hand side of jack 380a.

As shown in FIG. 16, a jack 391 has normal input leads 392 connected by contacts 393 to one side of the circuit 394 which circuit is connected by contacts 395 to normal output conductors 396. Upon insertion of a plug 397 circuit 394 is taken out of the through circuitry and a patch circuit 398 connected to plug 397 is inserted in its place.

STRUCTURAL MODIFICATION OF FIGS. 5 TO 7 FIGS. 5, 6, and 7 show a modified embodiment 430 of a multi-circuit switching connector according to the present invention. The connector of this embodiment includes a jack assembly 431 and plugs 432 insertable therein.

As best shown in FIGS. 5 and 6, jack 431 has a main body portion 434 preferably made from a synthetic resin or plastic material and has two spaced, longitudinal, parallel bores 436 and 438 therein. Tubular jack barrels 440 and 442 are inserted respectively in jack body bores 436 and 438 with a tight, permanent fit. Adjacent the front end 444 of jack body 434, the upper portion of the jack body is cut away at 445 to expose the jack switching arrangement, the cut away section terminating in respective horizontal surfaces 446 and 448 outboard of bores 436 and 438 and a central horizontal surface 450 therebetween. Jack barrels 440 and 442 are partially cut away throughout a portion coextensive with cut away portion 445 to provide operating space for the connector switching arrangements described below.

A set of electrically connected cantilever springs 456 are mounted in respective grooves 458 formed in surface 446 and extend across cut away portion 452 of jack barrel 440 to ter minate adjacent the central horizontal surface 450 of the jack body. Cantilever springs 460 of a second set are mounted in respective grooves 462 formed in surface 448 and terminate adjacent the central surface 450. A set of shorting bars 464 are mounted transversely upon central surface 450 in alignment with cantilever springs 456 and 460. Springs 456 and 460 have terminal contacts 466 and 468, respectively, which are normally maintained in spring biased contact with shorting bars 464, and have intermediate contacts 470 and 472, which are positioned in substantially vertical alignment over the axes of barrels 440 and 442, respectively. Springs 456 and 460 are in electrical contact with conducting pins 474 and 476, respectively, (FIG. 6) extending downwardly through jack body 434 and a printed circuit board 480 to form an electrical connection with one of a plurality of printed circuits 478 and 479 thereon.

As further shown in FIG. 5, jack barrels 440 and 442 contain respective compression springs 482 and 484 and plug contacting plungers 486 and 488 at the rear ends thereof. The springs are secured to the inner end of the jack barrels by pins 490 and 492, respectively.

Insulating strips 494 and 496 (FIG. 6) are secured to jack body upon surfaces 446 and 448 over the ends of the cantilever springs. The insulating strips and the cantilever springs are retained in position by respective brass strips 498 and 500 contacting the upper surface of the insulating strips and secured to the jack body 434 by fasteners 501.

Printed circuits 478 and 479, respectively, lead from the vertical pins 474 and 476 and extend longitudinally along the circuit board 480 to the rear of jack 431. Suitable pin connectors 502 are there provided to interconnect printed circuits 478 and 479 with the pin-like conductors 504 of a connector 506 mounted in the rear end of jack 431 to connect with a jack cable adapter unit (not shown) similar to the unit 38 shown in the embodiment of FIGS. 1 to 4.

As shown in FIGS. 5 and 6, jack barrels 440 and 442 have longitudinal alignment slots 508 and 510, respectively, extending along the bottom thereof from the front of the barrels almost completely to the rear thereof. At the rear of slots S08 and 510, they are enlarged laterally as at 512 and 514 to form a bayonet recess on one side of the slots.

As best shown in FIG. 7, plugs 432 each have an outer brass shell 518 surrounding an inner insulating shell 520 which may be made of Teflon. Within Teflon shell 520, a plurality of brass cam discs 522 are assembled in longitudinally aligned relation and are separated from each other by similarly shaped insulating discs 524 (FIG. 5), which may also be made from teflon, to form a longitudinally uniform plug. Cam discs 522 and 524 are all provided with a cam projection 526 for purposes described below and are further provided with a longitudinal bore 528 extending therethrough. The brass cam discs 522 are electrically connected to the individual conductors 530 of a multiconductor plug cord by respective connecting means 532 such as solder.

As shown further in FIG. 2, plug 432 is inserted in jack barrel 442 with a key 516 in line with a slot 508 in the jack barrel. Upon complete axial insertion of plug 432, the plug can be twisted clockwise through a partial turn as the key 116 on the plug is then aligned with bayonet recess 514 in the jack barrel. Upon releasing plug 432 in its engaged position, spring 484 tends to press key 516 into engagement with the front edge of recess 514 thus retaining plug 432 injack barrel 442.

As shown in FIG. 7, the cam portions 526 are clear of contacts 472 on the cantilever springs 460 during axial insertion of the plug with its key 516 aligned in slot 508 in the jack barrel. However, as shown in FIG. 6, when plug 432 is turned clockwise cam portions 526 engage contacts 472 and actuate cantilever springs 460 to open the contact between the springs and the center shorting bars 464 of the jack.

Thus, the switching connections between the various sets of parallel conductors is accomplished in the embodiment of FIGS. 5 to 7 in a manner similar to that described above for the embodiment of FIGS. 1 to 4.

STRUCTURAL MODIFICATION OF FIGS. 8 to 10 A further embodiment of a connector according to the present invention is shown in FIGS. 8, 9, and 10, and as shown in FIGS. 8 and 9, a jack 602 of this embodiment includes a sheet metal frame 604 having a short vertical upstanding leg 606 at the front end thereof. At the rear end of frame 604, a vertically upstanding transverse block 608 is provided. Extending between leg 606 and block 608 are two tubular jack barrels 610 and 612 which terminate within block 608 and extend through leg 606 at the front of the jack.

A pair of insulating, spring strip support blocks 614 and 616 are mounted on frame 604 outboard of tubular jack barrels 610 and 612 between upstanding leg 606 and block 608. Support blocks 614 and 616 support one end of a plurality of spring contact strips 618 and 620, respectively, which extend transversely across the top of jack barrels 610 and 612 to terminate in respective center contacts 622 and 624 which are normally urged by the bias of the spring strips into engagement with respective contact spots 626 and 628 on an insulating center contact block 630 mounted on frame 604 by a pair of screw and nut assemblies 632 (only one shown). Contacts 626 and 628 are interconnected within block 630 to form a plurality of parallel straight through circuits.

Spring strips 618 and 620 are retained on support blocks 614 and 616 by insulating cap strips 634 and 636 which also provide suitable electrical connections 638 and 640 to which lead wires 642 and 644 may be connected. The lead wires extend to the rear of jack 602 through a longitudinally extending shallow groove 646 cut in the upper surface of a plate 648 mounted upon block 608 and upon spacers 650 on spring strip support blocks 614 and 616. Lead wires 642 and 644 are suitably connected to a plurality of pin-like connectors 652 and 654 mounted in insulating plate 656 mounted upon the rear of jack 602 by a pair of L-shaped brackets 658 which in turn are mounted on frame 604 under the transverse block 608. The various components of jack 602 are retained on frame 604 thereof by means of screw and nut assemblies 660.

Jack barrels 610 and 612 have their tubular side walls cut away at 661 throughout an upper intermediate portion directly under the spring strips 618 and 620. The spring strips are provided with plug contacts 662 positioned over the cut away portions 661 of the jack barrels.

As shown in FIG. 10, one of a pair of plugs 670 engageable with jack 602 includes a single rod like plug member 672 having a plurality of longitudinally aligned, axially spaced contacts 674 thereon. Contacts 674 are electrically connected to individual conductors 676 of plug cord 678 which extends through an opening 680 in the end of a grip 682 which threadedly engages an enlarged portion 684 of plug member 672. Plug 670 is further provided with an alignment key 686 for engagement with alignment slots 688 and 690 of the jack barrel.

As in the above embodiments, the plug may be inserted in the jack in such rotational position that no switching of circuits occurs. Upon full insertion of the plug, it may be turned slightly clockwise to affect circuit switching as alignment key 686 then engages a bayonet like enlargement (not shown) in the alignment slots 688 and 690 of the jack barrels. The electrical circuit switching of this embodiment is similar to that described above for the embodiment of FIGS. 1 to 4.

The invention may be embodied in other specific forms without departing from the spirit of essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the

scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A multi-conductor switching connector comprising:

a. a jack body having mounted therein first and second parallel, adjacent jack barrels each having an intermediate, partially cut away portion;

. a plurality of parallel, spaced shorting bars mounted on said body transverse to and between said barrels adjacent the cut away portions thereof;

. a plurality of first cantilever spring switches mounted on said body outboard of said cut away portion of said first barrel and extending thereacross to normally contact one end of said shorting bars;

d. a plurality of second cantilever spring switches mounted on said body outboard of said cut away portion of said second barrel and extending thereacross to normally contact the other end of said shorting bars;

e. input leads connected to said first cantilever spring switches:

f. output leads connected to said second cantilever spring switches; and

g. a first and a second plug for insertion in said first and second barrels, respectively, each plug having a plurality of conductors each having a switch contacting and actuating member connected respectively thereto, said plugs in said barrels having coacting guide means permitting and defining paths for longitudinal insertion of the plugs into said barrels to predetermined depths and permitting limited rotation of said plugs relative to said barrels when said plugs are fully inserted into said barrels, said switch contacting and actuating members projecting from said plugs and being effective upon a rotation of said plugs after complete insertion thereof to engage and lift the respective spring switches from the shorting bars and to connect said conductors to said switches.

. A multi-conductor switching coupler comprising:

. a jack body having:

1. a pair of adjacent parallel plug receiving sockets open at one end to permit insertion ofa plug;

2. a set of electrically parallel shorting elements on said body intermediate said sockets;

3. a first set of contact elements movably mounted on said body and normally engaged with one end of said shorting elements;

4. a second set of contact elements mounted on said body and normally engaged with said shorting elements;

said first set of contact elements being disposed in longitudinally spaced relation along one of said sockets, said second set of contact elements being disposed in longitudinally spaced relation along the other of said sockets, each of said contact elements of said first and second sets having an actuator element thereon disposed relative to the associated socket in a position to be engaged and moved by movement of a plug in such associated socket,

b. a first plug having a set of conductors, means on said first plug operative when said first plug is inserted into said one socket of said jack and rotated therein to engage the actuator elements of and actuate said first set of contact elements to disconnect said first set of contact elements from said shorting elements and to connect said first set of contact elements to said set of conductors of said first plug, and

c. a second plug having a set of conductors, means on said second plug operative when said second plug is inserted into said other socket of said jack and rotated therein to engage the actuator elements of and actuate said second set of contact elements to disconnect said second set of contact elements from said shorting elements and to connect said second set of contact elements to said set of conductors of said second plug.

3. The switching coupler as described in claim 2 further comprising a set of electrically parallel input leads connected to said first set of contact elements and printed on a portion of said jack body, a set of electrically parallel output leads connected to said second set of contact elements and printed on a further portion of said jack body, and a plurality of terminals at the end of said jack body remote from the open ends of said sockets, each of such leads being electrically connected to one of said terminals.

4. A multi-circuit plug-in switching connector comprising a jack defining a socket having a longitudinal axis along which a plug may be inserted; said jack having a first set of mutually insulated contact elements each disposed in a fixed longitudinal relation along said axis in a single row parallel to said axis, means mounting said first set of contact elements for limited movement transversely of said axis between longitudinally aligned normal positions and longitudinally aligned shifted positions spaced from said normal positions transversely of said axis, said jack having a second set of contact elements disposed in a single row extending longitudinally of said axis, means mounting each of said second set of contact elements in a fixed longitudinal relation along said axis and in a position in which each is engaged by one contact element of said first set in one of the two said positions of said first set; and a plug having a third set of mutually insulated fixed contact elements, means mounting said third set of contact elements of said plug in a longitudinally spaced relation similar to that of said first set of contact elements, coacting means on said plug and socket permitting insertion of said plug into said socket only in a predetermined angular orientation and coacting means on said plug and socket permitting limited angular rotation of said plug in said socket when said plug is fully longitudinally seated in said socket, means operatively connected to the contact elements of said first set and disposed in the paths of rotation of the contact elements of said third set while said plug is fully longitudinally seated in said socket and operative upon engagement by the contact elements of said third set to shift the contact elements of the first set from their normal to their shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of the third set.

5. The connector as described in claim 4 wherein said mounting for the contact elements of said first set comprises a plurality of cantilever spring members extending transverse to said axis.

6. The switching connector as described in claim 37 wherein the respective contact elements of said second and third sets are electrically interconnected and wherein said jack member includes a first and a second set of electrically interconnected auxiliary contacts mounted thereon to through connect the respective switches of said first and fourth sets when the latter are in their normal position whereby when one of said plugs is inserted in said jack, the electrical connection from said first to said fourth sets of switches is broken and may be reestablished only through the electrically connected con tacts of said first and second plugs when the latter is also inserted.

7. The switching connector defined in claim 4 wherein the contact elements of the second set are mutually insulated.

8. The switching connector defined in claim 4 wherein the contact elements of said second set engage the contact elements of said first set in the normal position of said first set.

9. A multi-circuit switching connector as defined in claim 4 wherein, in said predetermined angular orientation of the plug and jack during axial insertion of the plug into the jack, there is a predetermined clearance between the contact elements of said third set and the contact elements of said first and second set precluding electrical conduction therebetween.

10. A multi-circuit switching connector comprising:

a. an elongated jack member having a longitudinal axis and paired first and second sets of contact elements, means mounting the contact elements of each of said sets in longitudinally aligned rows parallel to but spaced transversely of said axis and in longitudinally spaced relation therealong, means resiliently biasing said contact elements to normal positions,

b. an axially elongated plug insertable in said jack member, said plug having third and fourth sets of longitudinally spaced contact elements, said third set of contact elements on said plug being arranged in longitudinally spaced relation along a rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug, said fourth set of contact elements of said plug being arranged in longitudinally spaced relation along a second rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug but spaced circumferentially from said first set; the contact elements of said third and fourth sets being located in radially spaced relation from the surface of the remainder of said plug, means operatively connected to the contact elements of said first and second sets and disposed in the paths of rotation of the contact elements of said third and fourth sets of contact elements on said plug when fully longitudinally seated in said jack member and operative upon engagement by the contact elements of said third and fourth sets to shift the contact elements of the first and second sets from their normal to shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of said third set and each of the contact elements of the second set with a longitudinally aligned one of the contact elements of said fourth set, said jack including a first and a second set of auxiliary contacts, means mounting said first and second sets of auxiliary contacts in a position to be engaged by and in electrical contact with the respective first and second sets of contact elements when the latter are in their normal spring biased position and disengaged therefrom when the latter are shifted from their normal position whereby said plug is effective upon insertion into said jack to switch the electrical connection of the respective jack contact elements from the jack auxiliary contacts to the contact elements of said plug.

1 l. A multi-circuit switching connector comprising:

a. an elongated jack member having a longitudinal axis and paired first and second sets of contact elements, means mounting the contact elements of each of said sets in iongitudinally aligned rows parallel to but spaced transversely of said axis and in longitudinally spaced relation therealong for movement between normal and transferred positions, means resiliently biasing said contact elements to their normal positions,

b. an axially elongated plug insertable in said jack member said plug having third and fourth sets of longitudinally spaced contact elements, said third set of contact elements on said plug being arranged in longitudinally spaced relation along a rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug, said fourth set of contact elements of said plug being arranged in longitudinally spaced relation along a second rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug but spaced circumferentially from said third set; the contacts of said third and fourth sets being located in radially spaced relation from the surface of the remainder of said plug, means operatively connected to the contact elements of said first and second sets and disposed in the paths of rotation of the contact elements of said third and fourth sets of contact elements on said plug when fully longitudinally inserted in said jack member and operative upon engagement by the contact elements of such third and fourth sets to shift the contact elements of said first and second sets from their normal to shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of said third set and each of the contact elements of the second set with a longitudinally aligned one of the contact elements of said fourth set, the respective paired contact elements of said first and said second sets each including a contact thereon the contacts of each pair of contact elements of said first and second sets being normally engaged to electrically interconnect the contact elements of each pair when said contact elements are in their normal positions and disengaged when said contact elements are in their transferred positions whereby upon insertion of said plug said contact elements are moved from their normal to their transferred positions and the electrical connections between said first and said second sets of contact elements is broken and electrical contact is established between respective contact elements of said sets of said jack and the contacts of said plug.

12. A multi-circuit switching connector comprising:

a. an elongated jack member having a pair of sockets each having a longitudinal axis and paired first and second and third and fourth sets of contact elements, means mounting the contact elements of each of said first and second sets in longitudinally aligned rows parallel to but spaced transversely of said first axis and in longitudinally spaced relation therealong, means similarly mounting said third and fourth sets along said second axis, said mounting means mounting each of said contact elements for movement between normal and transferred positions and resiliently biasing said contact elements to their normal positions,

b. a pair of axially elongated plugs each insertable in said jack member in one of said sockets, said plugs each having first and second sets of longitudinally spaced contacts, said first set of contacts on each of said plugs being arranged in longitudinally spaced relation along a rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug, said second set of contacts of each of said plugs being arranged in longitudinally spaced relation along a second rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug but spaced circumferentially from the first set thereon; the contacts of said first and second sets on said plugs being located in radially spaced relation from the surface of the remainder of said means operatively connected to the contact elements of said first and second sets and disposed respectively in the paths of rotation of said first and second sets of contacts on one of said plugs when fully longitudinally seated in the associated one of said pair of sockets on said jack member and operative upon engagement by the contacts of said first and second sets on said one plug to shift the contact elements of said first and second sets from their normal to shifted positions and engage each of the contact elements of said third and fourth sets with a longitudinally aligned one of said contacts on said other plug.

13. A multi-circuit plug-in switching connector comprising a jack defining a socket having a longitudinal axis along which a plug may be inserted, said jack having a first set of mutually insulated contact elements each disposed in a fixed longitudinal relation along said axis in a single row parallel to said axis, means mounting said first set of contact elements for limited movement transversely of said axis between longitudinally aligned normal positions and longitudinally aligned shifted positions spaced from said normal positions transversely of said axis said jack having a second set of contact elements disposed in a single row extending longitudinally of said axis, means mounting each of said second set of contact elements in a fixed longitudinal relation along said axis and in a position in which each is engaged by one contact element of said first set in one of the two said positions of said first set; a plug having a third set of mutually insulated fixed contact elements, means contact elements of said first set of contacts and disposed in the paths of rotation of said third set during said limited angular rotation while said plug is fully longitudinally seated in said socket to engage and shift the contact elements of the first set from their normal to their shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of the third set.

Patent No.

Inventor(s) Col. 2,

- Col. 3

Col. 3,

Col. 4

(SEAL) Attest':

EDWARD M.FLETCHER,JRQ

D t Mav 23, 1972 Jesse F, Lancaster line 10, line 50, change "37" to =-=-12--. (see page 4-, Amendment B filed May 25,

Attesting Officer 'ORM PO-lOSO (10-69) It is certified that error appears in the 'aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

after "Figure" insert --l1--.

change "block" to -b1ocks-=..

change "pine" to --=pins--,

change "pine" to -pinschange "252" to --242--,.

after "19" insert --inch-.

change "2 to --7-.

change "116" to -5l6--.

12, line 47, after "said" insert --plug,--. (The Patent Office failed to completely delete this amendment of June 15, 1966, in line 29 of claim 37 as directed in Amendment D, page 3 filed June 29,

In References Cited, change "Chestnut et al" to --Chestnutt et al Signed and sealed this 19th day of September 1972.

ROERI GOTTSCHALK Commissioner of Patents USCOMM-DC B0376-P69 1' U5, GOVERNMENT PRINTING OFFICE: I969 0-365-334 

1. A multi-conductor switching connector comprising: a. a jack body having mounted therein first and second parallel, adjacent jack barrels each having an intermediate, partially cut away portion; b. a plurality of parallel, spaced shorting bars mounted on said body transverse to and between said barrels adjacent the cut away portions thereof; c. a plurality of first cantilever spring switches mounted on said body outboard of said cut away portion of said first barrel and extending thereacross to normally contact one end of said shorting bars; d. a plurality of second cantilever spring switches mounted on said body outboard of said cut away portion of said second barrel and extending thereacross to normally contact the other end of said shorting bars; e. input leads connected to said first cantilever spring switches: f. output leads connected to said second cantilever spring switches; and g. a first and a second plug for insertion in said first and second barrels, respectively, each plug having a plurality of conductors each having a switch contacting and actuating member connected respectively thereto, said plugs in said barrels having coacting guide means permitting and defining paths for longitudinal insertion of the plugs into said barrels to predetermined depths and permitting limited rotation of said plugs relative to said barrels when said plugs are fully inserted into said barrels, said switch contacting and actuating members projecting from said plugs and being effective upon a rotation of said plugs after complete insertion thereof to engage and lift the respective spring switches from the shorting bars and to connect said conductors to said switches.
 2. A multi-conductor switching coupler comprising: a. a jack body having:
 2. a set of electrically parallel shorting elements on said body intermediate said sockets;
 3. a first set of contact elements movably mounted on said body and normally engaged with one end of said shorting elements;
 3. The switching coupler as described in claim 2 further comprising a set of electrically parallel input leads connected to said first set of contact elements and printed on a portion of said jack body, a set of electriCally parallel output leads connected to said second set of contact elements and printed on a further portion of said jack body, and a plurality of terminals at the end of said jack body remote from the open ends of said sockets, each of such leads being electrically connected to one of said terminals.
 4. A multi-circuit plug-in switching connector comprising a jack defining a socket having a longitudinal axis along which a plug may be inserted; said jack having a first set of mutually insulated contact elements each disposed in a fixed longitudinal relation along said axis in a single row parallel to said axis, means mounting said first set of contact elements for limited movement transversely of said axis between longitudinally aligned normal positions and longitudinally aligned shifted positions spaced from said normal positions transversely of said axis, said jack having a second set of contact elements disposed in a single row extending longitudinally of said axis, means mounting each of said second set of contact elements in a fixed longitudinal relation along said axis and in a position in which each is engaged by one contact element of said first set in one of the two said positions of said first set; and a plug having a third set of mutually insulated fixed contact elements, means mounting said third set of contact elements of said plug in a longitudinally spaced relation similar to that of said first set of contact elements, coacting means on said plug and socket permitting insertion of said plug into said socket only in a predetermined angular orientation and coacting means on said plug and socket permitting limited angular rotation of said plug in said socket when said plug is fully longitudinally seated in said socket, means operatively connected to the contact elements of said first set and disposed in the paths of rotation of the contact elements of said third set while said plug is fully longitudinally seated in said socket and operative upon engagement by the contact elements of said third set to shift the contact elements of the first set from their normal to their shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of the third set.
 4. a second set of contact elements mounted on said body and normally engaged with said shorting elements; said first set of contact elements being disposed in longitudinally spaced relation along one of said sockets, said second set of contact elements being disposed in longitudinally spaced relation along the other of said sockets, each of said contact elements of said first and second sets having an actuator element thereon disposed relative to the associated socket in a position to be engaged and moved by movement of a plug in such associated socket, b. a first plug having a set of conductors, means on said first plug operative when said first plug is inserted into said one socket of said jack and rotated therein to engage the actuator elements of and actuate said first set of contact elements to disconnect said first set of contact elements from said shorting elements and to connect said first set of contact elements to said set of conductors of said first plug, and c. a second plug having a set of conductors, means on said second plug operative when said second plug is inserted into said other socket of said jack and rotated therein to engage the actuator elements of and actuate said second set of contact elements to disconnect said second set of contact elements from said shorting elements and to connect said second set of contact elements to said set of conductors of said second plug.
 5. The connector as described in claim 4 wherein said mounting for the contact elements of said first set comprises a plurality of cantilever spring members extending transverse to said axis.
 6. The switching connector as described in claim 37 wherein the respective contact elements of said second and third sets are electrically interconnected and wherein said jack member includes a first and a second set of electrically interconnected auxiliary contacts mounted thereon to through connect the respective switches of said first and fourth sets when the latter are in their normal position whereby when one of said plugs is inserted in said jack, the electrical connection from said first to said fourth sets of switches is broken and may be reestablished only through the electrically connected contacts of said first and second plugs when the latter is also inserted.
 7. The switching connector defined in claim 4 wherein the contact elements of the second set are mutually insulated.
 8. The switching connector defined in claim 4 wherein the contact elements of said second set engage the contact elements of said first set in the normal position of said first set.
 9. A multi-circuit switching connector as defined in claim 4 wherein, in said predetermined angular orientation of the plug and jack during axial insertion of the plug into the jack, there is a predetermined clearance between the contact elements of said third set and the contact elements of said first and second set precluding electrical conduction therebetween.
 10. A multi-circuit switching connector comprising: a. an elongated jack member having a longitudinal axis and paired first and second sets of contact elements, means mounting the contact elements of each Of said sets in longitudinally aligned rows parallel to but spaced transversely of said axis and in longitudinally spaced relation therealong, means resiliently biasing said contact elements to normal positions, b. an axially elongated plug insertable in said jack member, said plug having third and fourth sets of longitudinally spaced contact elements, said third set of contact elements on said plug being arranged in longitudinally spaced relation along a rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug, said fourth set of contact elements of said plug being arranged in longitudinally spaced relation along a second rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug but spaced circumferentially from said first set; the contact elements of said third and fourth sets being located in radially spaced relation from the surface of the remainder of said plug, means operatively connected to the contact elements of said first and second sets and disposed in the paths of rotation of the contact elements of said third and fourth sets of contact elements on said plug when fully longitudinally seated in said jack member and operative upon engagement by the contact elements of said third and fourth sets to shift the contact elements of the first and second sets from their normal to shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of said third set and each of the contact elements of the second set with a longitudinally aligned one of the contact elements of said fourth set, said jack including a first and a second set of auxiliary contacts, means mounting said first and second sets of auxiliary contacts in a position to be engaged by and in electrical contact with the respective first and second sets of contact elements when the latter are in their normal spring biased position and disengaged therefrom when the latter are shifted from their normal position whereby said plug is effective upon insertion into said jack to switch the electrical connection of the respective jack contact elements from the jack auxiliary contacts to the contact elements of said plug.
 11. A multi-circuit switching connector comprising: a. an elongated jack member having a longitudinal axis and paired first and second sets of contact elements, means mounting the contact elements of each of said sets in longitudinally aligned rows parallel to but spaced transversely of said axis and in longitudinally spaced relation therealong for movement between normal and transferred positions, means resiliently biasing said contact elements to their normal positions, b. an axially elongated plug insertable in said jack member said plug having third and fourth sets of longitudinally spaced contact elements, said third set of contact elements on said plug being arranged in longitudinally spaced relation along a rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug, said fourth set of contact elements of said plug being arranged in longitudinally spaced relation along a second rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug but spaced circumferentially from said third set; the contacts of said third and fourth sets being located in radially spaced relation from the surface of the remainder of said plug, means operatively connected to the contact elements of said first and second sets and disposed in the paths of rotation of the contact elements of said third and fourth sets of contact elements on said plug when fully longitudinally inserted in said jack member and operative upon engagement by the contact elements of such third and fourth sets to shift the contact elements of said first and second sets from their normaL to shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of said third set and each of the contact elements of the second set with a longitudinally aligned one of the contact elements of said fourth set, the respective paired contact elements of said first and said second sets each including a contact thereon the contacts of each pair of contact elements of said first and second sets being normally engaged to electrically interconnect the contact elements of each pair when said contact elements are in their normal positions and disengaged when said contact elements are in their transferred positions whereby upon insertion of said plug said contact elements are moved from their normal to their transferred positions and the electrical connections between said first and said second sets of contact elements is broken and electrical contact is established between respective contact elements of said sets of said jack and the contacts of said plug.
 12. A multi-circuit switching connector comprising: a. an elongated jack member having a pair of sockets each having a longitudinal axis and paired first and second and third and fourth sets of contact elements, means mounting the contact elements of each of said first and second sets in longitudinally aligned rows parallel to but spaced transversely of said first axis and in longitudinally spaced relation therealong, means similarly mounting said third and fourth sets along said second axis, said mounting means mounting each of said contact elements for movement between normal and transferred positions and resiliently biasing said contact elements to their normal positions, b. a pair of axially elongated plugs each insertable in said jack member in one of said sockets, said plugs each having first and second sets of longitudinally spaced contacts, said first set of contacts on each of said plugs being arranged in longitudinally spaced relation along a rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug, said second set of contacts of each of said plugs being arranged in longitudinally spaced relation along a second rectilinear row parallel to the axis of said plug and extending over but a limited arcuate extent of the circumference of said plug but spaced circumferentially from the first set thereon; the contacts of said first and second sets on said plugs being located in radially spaced relation from the surface of the remainder of said means operatively connected to the contact elements of said first and second sets and disposed respectively in the paths of rotation of said first and second sets of contacts on one of said plugs when fully longitudinally seated in the associated one of said pair of sockets on said jack member and operative upon engagement by the contacts of said first and second sets on said one plug to shift the contact elements of said first and second sets from their normal to shifted positions and engage each of the contact elements of said third and fourth sets with a longitudinally aligned one of said contacts on said other plug.
 13. A multi-circuit plug-in switching connector comprising a jack defining a socket having a longitudinal axis along which a plug may be inserted, said jack having a first set of mutually insulated contact elements each disposed in a fixed longitudinal relation along said axis in a single row parallel to said axis, means mounting said first set of contact elements for limited movement transversely of said axis between longitudinally aligned normal positions and longitudinally aligned shifted positions spaced from said normal positions transversely of said axis said jack having a second set of contact elements disposed in a single row extending longitudinally of said axis, means mounting each of said second set of contact elements in a fixed longitudinal relation along said axis and in a position in which each is Engaged by one contact element of said first set in one of the two said positions of said first set; a plug having a third set of mutually insulated fixed contact elements, means mounting said third set of contact elements in a longitudinally spaced relation similar to that of said first set of contact elements; coacting means on said plug and socket permitting insertion of said plug into said socket in a predetermined angular orientation of said plug and socket; coacting means on said plug and socket effective only after said plug is fully longitudinally seated in said socket to permit limited angular rotation of said plug in said socket; means operatively connected to the contact elements of said first set of contacts and disposed in the paths of rotation of said third set during said limited angular rotation while said plug is fully longitudinally seated in said socket to engage and shift the contact elements of the first set from their normal to their shifted positions and engage each of the contact elements of the first set with a longitudinally aligned one of the contact elements of the third set. 